Noel's method will fix the current issue, but to avoid future issues, it may be well worth making sure the recording signal is at a decent level to begin with, otherwise you can also be raising the noise level when you boost the track like that. The more tracks you boost the more noise.

Better to make sure you are recording a good signal from the start than boost a poor recording later.
Just my thoughts, thus my above post.

We've all used Noel's method, but really not the best solution for the problem moving forward if your initial levels are indeed too low.
Getting the input level correct can avoid boosting all your recordings in the future.

I do not work here, but the benefits are still awesome
Make your sound your own!